1670661720 has 512 divisors, whose sum is σ = 6967296000. Its totient is φ = 346705920.

The previous prime is 1670661719. The next prime is 1670661739. The reversal of 1670661720 is 271660761.

1670661720 is a `hidden beast` number, since 16 + 7 + 0 + 6 + 617 + 20 = 666.

It is a super-2 number, since 2×1670661720² = 5582221165346716800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 8746825 + ... + 8747015.

It is an arithmetic number, because the mean of its divisors is an integer number (13608000).

Almost surely, 2^1670661720 is an apocalyptic number.

1670661720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1670661720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3483648000).

1670661720 is an abundant number, since it is smaller than the sum of its proper divisors (5296634280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1670661720 is a wasteful number, since it uses less digits than its factorization.

1670661720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 36.

The square root of 1670661720 is about 40873.7289710640. The cubic root of 1670661720 is about 1186.5776774716.

The spelling of 1670661720 in words is "one billion, six hundred seventy million, six hundred sixty-one thousand, seven hundred twenty".